Screen flashing/flickering after update to OS v9.0
(Device Model 3800X)
Had to reset the device for it to stop flickering, daily.
The problem was the free HDMI extender sent to me by Roku.
After removing it, the flashing stopped and I no longer need to reset the device.
I have the same issue with my TCL 49S405 running Roku TV 7127X, version 8.2.0 build 4170-30. My issue is when I run a refresh rate of 60hz I get the fluttering and my sound is only garbled crackling. If I switch down to 30hz it's no problem. I'm using HDMI 2.0 and I just bought this TV instead of the Toshiba 50" 4K I got for Christmas. I chose the Toshiba because it had fire tv versus roku. I've had nothing but problems with Roku in the past and here we go again. This is my 4th TV in the last 30 days because I was trying to stay with Fire TV. After purchasing and returning every model because of poor screen performance I was FORCED to go with roku because TCL only ships with Roku. It's worth noting that all three prior TV's ran fine at 60hz.
Also, I have read multiple posts online at reddit and other sites where roku is aware of this issue with the recent build but haven't corrected it The reason I went to the trouble to register and reply to this forum is because I saw a Roku rep asking questions to waste our time ande spin our wheels versus acknowledging the error they already know about and correcting ti. I'm going to have to return this TV even though TCL has the best picture by far in the under $500 4k market.
I dealt with roku and their limitations when they first came out trying to compete against the apple tv. They were flawed then and they are flawed now in design, execution, and customer service.
I have a Roku 3, 4200X and the December 16, 2017 update "broke" 1080p playback for me too ... the video flickers and flashes while the audio cuts in and out on one of my three Panasonic plasmas. Forcing 720p restores stable audio and video. The updated Roku fails on my 2011 TC-P65VT30 but works fine on both my 2009 TC-P42G15 and my 2012 TC-P50ST50.
I have been getting diagnostic and troubleshooting help from Roku Support. They have been responsive but have failed to resolve or replicate this issue. Please, if you're experiencing this, reach out and give them your details...they clearly need more cases to identify the issue.
Here are all the troubleshooting things they had me try: Restart. Power off (disconnect plug for 60 seconds) and restart. Reseat HDMI cable. Change HDMI cable. Change HDMI port. Delete an affected channel and restart. Delete lots of channels and restart. (I deleted one and then 21 leaving 6 restarting in between the 1 and 21. Both of these despite seeing the flickering on the Roku home page and menus.) Set the theme to default and restart.
Nothing has worked. Hope enough of us will contact them so they can identify the issue and get a fix in the queue!
Happy (low resolution) Holidays!